DE 2 116 691 A describes a method for producing elastic compressed polyurethane foams. In a discontinuous process mode, the method herein described is performed by foaming the foamable polyurethane mixture in a usual mold, for example, a cardboard box, removing said mold from the partially cured foam composition after lapse of the crush time while the previously mentioned temperature ranges are maintained, and compressing the foam composition. Preferably, the mold into which the foamable polyurethane mixture is fed is dimensioned so that the finished polyurethane foam can be used in this shape, or after a cutting process for removing the skin, which generally forms at the separating edges of the molded part.
DE 26 09 373 A1 relates to a mold for producing molded parts made of integral foam. It describes a molded part made of integral foam or similarly processable plastic foams, wherein said mold consists of two or more mold pieces, and the edges of the molded parts are pressed together joint-tightly. The purpose is to create a mold in which optimum aeration is obtained, and in which at the same time the molded part can be produced without drive-out burrs, without there being a risk of incomplete mold filling. This is to be achieved by having the support surfaces of the joints continuously as narrow as possible in the mold herein defined, and assigning control elements for the predetermined joint gap to the joints. At first, a small adjustable joint gap is used to ensure that only a relatively small proportion of the reaction mass gets outside the mold cavity through the joints. In addition, the narrow support surfaces of the joint enable the mold to be closed very tightly immediately after the foaming process. Because of the narrow support surface, the usual closing forces can achieve so high a specific pressure that the driven-out mass is squeezed directly at the mold edge.